<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="../2-apply.js"></script>
</head>
<body>
  <script>
    //声明一个函数
    function add(a,b){
      console.log(this);
      return a + b + this.c;
    }

    //声明一个对象
    let obj = {
       c:521
    };

    //添加全局属性
    window.c = 1314;

    //执行apply函数
    console.log(apply(add,obj,[10,20]));
    console.log(apply(add,null,[30,40]));
  </script>
</body>
</html>